Wallace j



Patented July 24, 1923.

UNITED "STATES PA Er oer-loci,

WALLACE J. MURRAY, 01? BOSTON, MASSACHUSETTS, ASSIG-NOE' TO ARTHUR I). LITTIEQE,

INC OF CAMBRIDGE, MASSACHUSETTS, A CORPORATION OF 'JPIIASSACHUSE TTSQ METHOD or rnonucrno azo comes n nonaounous SOLVENTS.

1% D awin To all whom it may concern Be it known that I, WALLACE J. MURRAY, a citizen of the United States, residing at Boston, in the county of Sufiolk and State 5 of Massachusetts, have invented certain new and useful Improvements in Methods of Producing Azo Colors in Nonaqueous Solvents; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The present invention relates to a method of producing azo colors in non-aqueous solvents, such as oils and materially increases the field of usefulness for such colors, as it enables their development in cases where the presence of water is undesirable.

Azo colors are produced by treating an amine with nitrous acid in order to secure a diazo compound which is in turn treated with a developer to obtain the color, these azo colors having been invariably prepared in a water solution in the past,

I have discovered that the preparation of the azo colors may be accomplished by treating a solution of the primary amine and developer in an oil, such as a liquid fatty acid, a glyceride, or hydro-carbon, containing a free acid, with sodium nitrite. Aside from the fact that this method produces colors directly in oil for use in inks and paints it has the decided advantage that the fatty acid or acidified oil will liberate nitrous acid from sodium nitrite and bring about diazotization without the use of water or mineral acids. In previous methods the use of a mineral acid was necessary to liberate nitrous acid from sodium nitrite, it being necessary to neutralize this acid before couplin between the diazo compound and the deve oper could take place. In addition, these mineral acids have a corrosive action which is injurious to certain metals withwhich the solution may be in contact.

As one example of the increased field of Application filed June 9,

of the paper The use of a fatty acid as a vehicle causes a completepenetration of the paper, whereas the ordinary water solution of a primary amine and developer would not penetrate the sized paperduring the printing operation to any appreciable extent.

.One specific example of my new method consists in treating a solution of beta-naphthol and dianisidine in oleic acid with sodium nitrite. The oleic acid first liberates nitrous acidfrom the sodium nitrite which in turn diazotizes the dianisidine, the diazotized amine immediately reacting ,7 or coupling with the beta-naphthol or developer to precipitate the azo color, dianisidine blue, in the oil. Due to the red color of the oleic acid, the resulting combination may be purple or brown. This azo color may be made more resistant to treatment with chemicals, such as bleaching agents and acids by mordanting. Various substances arecknown to textile dyers for this purpose, the most impor tant being metallic salts. Thesemetallic salts may be added to the mixture of oil, amine and developer; or they may be present in the material to be dyed, or they may be applied as an after-treatment.

The oil solvent forming a part of the pres ent invention is intended to embrace all fatty acids and similar oils which are capa ble of liberating free nitrous acid from sodium or amyl nitrites to bring about diazotization. Included inthis classification are fatty acids such as oleic acid and glycerides and hydro-carbons containing free acids, such as a solution of rosin in turpentine. J

I claim:

1. A method of producing azo colors in non-aqueous solvents which consists in com bining a solution of an amine and a developer in oil with a nitrite.

2. A method of producing azo colors in non-aqueous solvents whiclr consists in combining with a nitrite a solution of an amine and a developer in an oil capable of liberating freenitrous acid from the nitrite tocause diazotization of the amine by the nitrous acid.

3. A method of producing a'zo colors in non-aqueous solvents which consists in combining a nitrite with a solution of an amine and a developer in a fatty acid.

4;. A method of producing azo colors in non-aqueous solvents which consists in combining a nitrite with a solution of a primary amine and a'developer in oleic acid.

5. A method of producing azo colors in non-aqueous solvents which consists in combining a solution of dianisidine and betanaphthol in oleic acid with sodium nitrite to cause nitrous acid to be liberated by the oleic acid and diazotization of the dianisidine by the nitrous acid to take place, the

diazo compound so produced coupling with the beta naphthol to produce a colored pigment.

6. A method of producing azo colors in non-aqueous solvents which consists in combining a nitrite with a solution of an amine and a developer in liquid organic acid capable of liberating free nitrous acid from the nitrite.

WALLACE J MURRAY. 

